Difference between revisions of "Cardinality"
Jump to navigation
Jump to search
| Line 1: | Line 1: | ||
[[wikipedia:Cardinality]] is generally defined as the number of elements in a [[set]]. | [[wikipedia:Cardinality]] is generally defined as the number of elements in a [[set]]. | ||
| + | |||
| + | Calculating the exact cardinality of a [[multiset]] requires an amount of memory proportional to the [[cardinality]], which is impractical for very large data sets. The HyperLogLog algorithm is able to estimate cardinalities of > 109 with a typical accuracy (standard error) of 2%, using 1.5 kB of memory. | ||
Revision as of 13:44, 8 July 2022
wikipedia:Cardinality is generally defined as the number of elements in a set.
Calculating the exact cardinality of a multiset requires an amount of memory proportional to the cardinality, which is impractical for very large data sets. The HyperLogLog algorithm is able to estimate cardinalities of > 109 with a typical accuracy (standard error) of 2%, using 1.5 kB of memory.
FROM Metric SELECT cardinality(metric.name) SINCE today RAW
Activities
- Read about cardinality aggregation in Elasticsearch https://www.elastic.co/guide/en/elasticsearch/reference/current/search-aggregations-metrics-cardinality-aggregation.html
Advertising:
